import com.fasterxml.jackson.databind.ObjectMapper;

import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 86185
 * Date: 2023-10-14
 * Time: 15:43
 */
class Message {
    public String from;
    public String to;
    public String message;

    @Override
    public String toString() {
        return "Massage{" +
                "from='" + from + '\'' +
                ", to='" + to + '\'' +
                ", message='" + message + '\'' +
                '}';
    }
}
@WebServlet("/message")
public class message_servlet extends HttpServlet {
    private ObjectMapper objectMapper = new ObjectMapper();
//    private List<Massage> massageList = new ArrayList<>();
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Message message = objectMapper.readValue(req.getInputStream(), Message.class);

//        massageList.add(massage);
        try {
            save(message);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        System.out.println("服务器收到: " + message);
        resp.setStatus(200);
        resp.getWriter().write("ok");
    }

    private void save(Message message) throws SQLException {
        DataSource dataSource = new MysqlDataSource();
        ((MysqlDataSource) dataSource).setUrl("jdbc:mysql://127.0.0.1:3306/web?characterEncoding=utf8&useSSL=false");
        ((MysqlDataSource) dataSource).setUser("root");
        ((MysqlDataSource) dataSource).setPassword("111111");

        Connection connection = dataSource.getConnection();
        String sql = "insert into message values(?, ?, ?)";
        PreparedStatement statement = connection.prepareStatement(sql);
        statement.setString(1, message.from);
        statement.setString(2, message.to);
        statement.setString(3, message.message);
        statement.executeUpdate();
        statement.close();
        connection.close();
    }


    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        List<Message> massageList = null;
        try {
            massageList = load();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        String respJson = objectMapper.writeValueAsString(massageList);
        resp.setContentType("application/json; charset=utf8");
        resp.getWriter().write(respJson);
    }

    private List<Message> load() throws SQLException {
        DataSource dataSource = new MysqlDataSource();
        ((MysqlDataSource) dataSource).setUrl("jdbc:mysql://127.0.0.1:3306/web?characterEncoding=utf8&useSSL=false");
        ((MysqlDataSource) dataSource).setUser("root");
        ((MysqlDataSource) dataSource).setPassword("111111");

        Connection connection = dataSource.getConnection();
        String sql = "select * from message";
        PreparedStatement statement = connection.prepareStatement(sql);
        ResultSet resultSet = statement.executeQuery();
        List<Message> messages = new ArrayList<>();
        while (resultSet.next()) {
            Message message = new Message();
            message.from = resultSet.getString("from");
            message.to = resultSet.getString("to");
            message.message = resultSet.getString("message");
            messages.add(message);
        }
        resultSet.close();
        statement.close();
        connection.close();
        return messages;

    }
}
